1. Field of the Invention
The present invention relates in general to a security guard for a valve on a storage tank and more specifically concerns high strength valve guards that serve as a deterrent to the theft of toxic or hazardous materials.
2. Description of the Prior Art
Various types of valve security guards are known in the art for placement over valves and other regulating type devices used on storage containers to prevent any unlawful operation thereof. Examples of these prior art devices are disclosed in U.S. Pat. Nos. 4,380,247; 4,513,773; 4,254,888 and 4,899,781. Although the guards disclosed in such patents are useful for their designed purpose, none of them are structured to prevent unauthorized use of a dispensing valve for an anhydrous ammonia storage tank.